Explosive mines have long been used in warfare. Mines can be buried on land, anchored in the water, etc. For example, mines have been deployed in shallows, surf areas and beaches to defend against landings by offensive forces. For this purpose, mines can be sown in the Very Shallow Water (30 foot to 10 foot water depth) and Surf Zone (10 foot to 0 foot water depth) regions as well as on the beach itself. The Surf Zone starts at the 10-foot water depth and extends to the high water line on the beach. One method of neutralizing a series of mines in an intended landing or travel area is to individually locate each mine such as by probing or by using a metal detector, then placing an explosive charge on that mine, and then detonating that charge to neutralize the mine. Another method has been deployment of one or more Bangalore torpedoes. The Bangalore torpedo is a metal tube filled with explosives and equipped with a firing mechanism, particularly used for destroying barbed-wire entanglements, mine fields, etc. (S. B. Flexner, ed., The Random House Dictionary of the English Language, 2nd ed., unabridged (Random House, New York, 1987) page 163, 3rd column). The Bangalore torpedo is capable of clearing a narrow lane of a mine field. However, the Bangalore torpedo is both difficult and dangerous to deploy, especially if it is to be deployed while under fire. The series of metal tubes must be fitted together by hand on the battlefield near the location to be neutralized. This procedure thus leaves the users exposed to enemy gunfire. Since mines are usually deployed to be hidden from view, or at least made difficult to visually detect, such measures are difficult to accomplish, use up valuable time during which a defender could counterattack or otherwise react or respond to the offensive threat, and may prove ineffective if deployed mines are not neutralized in the intended area of travel.
Thus, there is a need for distributed explosives delivery, such as rocket-delivered explosives in support of in-stride amphibious assault such as in Surf Zone lane breaching. One such device is the rocket propelled M58A1 linear demolition charge, a 3100 pound system designed for ground emplacement and employment. Personnel and equipment handling this device are exposed to enemy gunfire when using this device because the time of exposure is long and there is little or no protection against direct or indirect fire. The line charge is transported into firing position by a forklift, crane or truck before installation of an accessory launcher rail for the rocket and assembly of the rocket firing connections. The M58 line charge and the MK22 rocket used therein and in the MICLIC are manufactured by Morton Thiokol, Shreveport, La. Both the M58A1 and its successor, the M58A3 or MICLIC, create a neutralized lane in a minefield about 10 meters wide and 100 meters long maximum against single impulse pressure actuated anti-tank mines. Another approach has been the trailer mounted MIne Clearing LIne Charge (MICLIC) system described in Required Operational Capability (ROC) No. LOG 1.63 for the Trailer Mounted Mine Clearing Line Charge (MICLIC) System, 7 Apr. 1983 (NTIS Accession Number AD A129426; also AD A127493) available from the National Technical Information Service, Springfield, Va., which document is hereby incorporated by reference herein. The MICLIC is a rocket-emplaced standard munition of the combat engineers in both the U.S. Army and the U.S. Marine Corps. The MICLIC employs a rocket to pull a rope-like explosive charge to clear a line of mines. The Mine Clearing Line Charge has been used for several years and most recently in Operation Desert Storm to supplant the hand emplaced Bangalore torpedo of World War II days. Details of the MICLIC, M58A3 can be found in the Mobility chapter of Army Field Manual No. 5-34, Engineer Field Data (Headquarters, Department of the Army, Washington, D.C., 14 Sep. 1987), which is hereby incorporated by reference herein. The mine-clearing line charge (MICLIC) is the U.S. Army terminology for the explosive system (M58 line charge) that is deployed from an M353 trailer. The M58 Linear Demolition Charge is approximately 350 feet long and consists of four sections of unit charges. A core of 3/4 inch nylon rope and three strands of 100-grain PETN detonating cord pass through each such section. The four sections are secured in a continuous line by connecting eye-splices in the two rope ends with links. The three strands of detonating cord of one section are secured to the three strands in the next section by use of detonating cord connectors. The linear demolition charge contains five pounds of Comp C4 explosive per linear foot, which is divided into unit charges each consisting of two, 51/2 by 11/2 by 21/2 inch rectangular pellets weighing 11/4 pounds each. The two pellets in each unit charge are wrapped in a plastic bag placed around the core of nylon rope and detonating cord, and secured with filament tape. The exterior of the charge is covered with two knitted nylon sleeves tied at the ends. A rocket harness connector is attached to the front end, and a demolition charge fuse connector is attached to the rear end, of the linear demolition charge. The rocket harness connector is used to attach the line charge to the bridle cable of a rocket. This rocket pulls the linear demolition charge out of the charge container when the rocket motor is fired. The MICLIC uses the MK22, MOD4 rocket motor, and M58 line charges, both manufactured by Morton-Thiokol, Shreveport, La.
It has been attempted to fire multiple MICLICs side by side to create a wider cleared lane. However, this has proven unfeasible in practice because while multiple MICLICs might be pointed in parallel before launch, individual rockets may have minor differences in physical or performance characteristics that are within manufacturing tolerances, but cause deviations in flight patterns sufficient to cause uncleared gaps left between the individual areas cleared thereby.
To avoid some of these shortcomings, an explosive net can be considered. Both the U.S. Marine Corps and the U.S. Navy have been working with the concept of distributed explosives. The Marine Corps approach has explosives at the intersections of a net, with individual detonators. This approach, called Distributed Explosive Mine Neutralization System (DEMNS), is intended for use in neutralizing mines on beaches. This net has open cells of approximate dimensions of 2 feet by 2 feet with an explosive charge at each intersection of the net cords. This DEMNS net is described in D. P. Wirtz, Preliminary Design and Accuracy Analysis of a Ground-Launched Multiple Rocket System for Breaching Mine Fields (NTIS Accession No. AD-A061 672), which is hereby incorporated by reference herein. The DEMNS net can have carbon-fiber stiffeners between the explosives. Once the net has been spread onto the mined area, the net is command-detonated. The Navy concept is a net entirely comprised of explosives, for use in water. The U.S. Navy is developing a linear array of explosives in a net in which almost the entire net is an explosive charge, with the same command detonation feature. These explosives nets promise a higher probability of mine clearance than the previously used mine-clearing charges such as the M58A3 (MICLIC).
However, difficulty has been encountered in deploying such nets. Since (as with the other approaches described above) such a net must be deployed from a location at the front of the area to be cleared, it is necessary to have the net extended both forward and sidewards in order to be effectively deployed. Initial attempts to have two rockets fired simultaneously in different directions to spread and deploy the net have worked under ideal conditions on test ranges, but there is some doubt concerning tactical feasibility. The primary problem with dual rocket approaches is reliably coordinating the timing and the trajectories so that the net is properly placed and does not foul on the launch vehicle. Obviously, fouling on the launch vehicle is hazardous both to the vehicle and its crew. It is therefore desirable to eliminate any reliance on simultaneous, dual-rocket launches for deployment of a net. Thus, there currently is no reliable means of deploying an explosive net into a mined area for neutralization of such an area. The present invention fulfills this need.
The Navy concept is called variously a Distributed Explosives Net and Distributed Explosives Technology System (DETS). Presently, the only Navy two-dimensional explosive charge array design(s) are in exploratory development, which means that no approved system now exists. As opposed to the Marine Corps developments for land mine clearance, the Navy initiatives are underway for the investigation of this approach for underwater applications. The MICLIC is considered to work moderately well against single impulse pressure plate land mines of the World War II type. It is not considered as useful in destroying mines through sympathetic detonation, but is considered to be a pressure influence type of neutralization mechanism which causes the mine to detonate by functioning the fuze by the air pressure impulse. Pressure to destruct mines is very dependent on the mine type but essentially mines are very difficult to destruct/damage with atmospheric overpressure. Mines are typically buried in the Surf Zone and on the beach up to 2 to 12 inches deep, depending on local environmental conditions. The purpose of distributive charges is to remove one dimension of randomness (the clearing charges are fixed in a known pattern) by controlling the distribution of small shaped charges (DEMNS), or with an array of line charges (DETS), over an area. The U.S. Navy is developing a net of explosives (DETS) for Surf Zone mine neutralization but does not have a reliable means of delivering the net to the target. The present invention fulfills this need.